Apparatus and method for hydrodynamic entanglement of non-wovens, wovens and knits

ABSTRACT

The invention relates to an apparatus and method for hydrodynamic entanglement of non-wovens, wovens and knits, comprising an entanglement system having at least one water bar and a drum or endless belt, between which a fibre web is transported and entangled. The invention is characterised in that before the water bar, seen in the running direction of the fibre web, there is arranged a compacting device, which compresses the fibre web on the drum or endless belt.

The invention relates to an apparatus and method for hydrodynamicentanglement of non-wovens, wovens and knits, comprising an entanglementsystem having at least one water bar and a drum or endless belt, betweenwhich a fibre web is transported and entangled.

In systems for the hydrodynamic entanglement of fibre webs, the fibreweb is compacted before entanglement by moistening and compressing thefibre web between two belts or between a belt and a drum. As a result,the non-woven web is slightly pre-entangled so that it is less fragilefor subsequent needling. Intertwining of the fibres is then carried outby twisting them with one another by means of high-pressure water jets.

Intertwining of the fibres is carried out using bars of nozzles, fromwhich high-pressure water jets strike the fibre web. The drum locatedunderneath the fibre web has a multiplicity of apertures, into which onthe one hand some of the fibres can extend and become intertwined and byway of which on the other hand the water of the water jets can be drawnoff under suction and drained off. Usually, 2-3 water bars are arrangedone after another. Without compacting, the fibre web is very fragile inrespect of the water jets and the suction drainage; the fibres wouldbecome displaced, which would negatively impact on the appearance of thefibre web and also on its strength and stretching. Without compacting,hydroentanglement of synthetic fibres such as polyester or polypropyleneis possible only to a limited degree. In that case great care andattention has to be paid to the correct pressure, to the spacing of thewater bar from the fibre web and to the associated suction drainage. Assoon as variations are found in the composition of the fibre web, allthe parameters have to be modified again and again. Reliable productionis not possible in the long term as a result. The known systems in theprior art comprise, for example, spunlace drums or hydroentanglementdrums. Alternatively, a corresponding endless belt is referred to as aspunlace belt or hydroentanglement belt.

It is disadvantageous that compaction of the fibre web causes the sizeof the system to increase and that the bars of nozzles with theassociated suction drainage arrangements are expensive.

The problem of the invention is to provide an apparatus and method forhydrodynamic entanglement of non-wovens, wovens and knits which iseconomical in terms of its construction and which ensures reliablecompaction before hydroentanglement by water jets.

The invention solves the addressed problem by means of the teachingaccording to claims 1 and 20; further advantageous embodying features ofthe invention are characterised by the subordinate claims.

In accordance with the technical teaching according to claim 1, theapparatus for hydrodynamic entanglement of non-wovens, wovens and knitscomprises an entanglement system having at least one water bar and adrum or an endless belt, between which a fibre web is transported andentangled.

In accordance with the invention, provision is made so that before thewater bar, seen in the running direction of the fibre web, there isarranged a compacting device, which compresses the fibre web on the drumor endless belt.

Using the features of the invention it is possible to make the existingsystem substantially shorter, by integrating the compacting device on orinto the entanglement system, which is to say the water bar and thedrum.

Advantageously, the compacting device has at least one compacting plate,which presses the fibre web onto the drum or endless belt. As a result,by the simplest of technical means, the same effect is achieved as inthe case of a compacting system installed upstream, in which the fibreweb is pre-compressed between endless belts or drums. It is possible todispense with an entire system section, giving rise to a considerableprice advantage.

As a result of the fact that the compacting plate is arranged to befixed to the water bar, a very compact unit is obtained, by means ofwhich the fibre web is first compressed and then entangled by means ofhigh-pressure water jets. The short time between compression andentanglement gives rise to advantages in terms of the strength of thefibre web and, at the same time, floating of the individual fibres isavoided, which results in a better non-woven product.

The water jet can have a pressure of from 10 to 100 bar. Optimum valuesare achieved using a pressure of from 20 to 40 bar.

Fixing the compacting plate to a carrier on the one hand makes possiblea solution which is capable of being retro-fitted and which can befixed, before the water bar, on the machine frame. On the other hand,the spacing of the compacting device to the fibre web can be adjustedindependently of the spacing of the water bar to the fibre web. Thecompacting device can, by means of a pivoting apparatus on the carrier,be adjusted in terms of angle and position so that the compression forceof the compacting plate on the non-woven web can be varied. Using thepivoting apparatus, the spacing from the trailing edge of the compactingplate to the row of water jets of the water bar can also be adjusted.

A further improvement is obtained as a result of the fact that thecompacting plate compresses the fibre web with biasing. The biasing canbe produced by the resilience of the compacting plate and/or by means ofa contact pressure application apparatus. Construction of the compactingplate from resilient metal or plastics especially produces an economicaland very effective compacting device because in the event ofirregularities in the material the readily bent metal or plastic stripsprings back. Furthermore, by utilising the resilience of the curvedcompacting plate, a certain run-in region is created, which is veryonerous to produce in the prior art by means of endless belts arrangedat an angle. By means of this run-in region, the fibres are compactedand are afterwards compressed in the region of the trailing edge of thecompacting plate.

A crucial advantage of the invention over the prior art is that atrailing edge of the compacting plate is positioned directly at thewater jet. By that means, the drawing-in of regions of the fibre webinto the suction region of the aperture or suction slits in the drum orbeneath the endless belt is prevented. The fibre web is better fixed tothe drum or endless belt whilst the individual fibres are beingintertwined with one another. The prior disadvantageous longitudinalstripes which occur when there is no compaction can be effectivelyprevented as a result.

In accordance with an advantageous embodiment, the trailing edge of thecompacting plate is positioned so close to the water jet that at leastpart of the suction region of the aperture or suction slits is coveredover. Only the fibres which are arranged in the region between thetrailing edge of the compacting plate and the row of water jets areintertwined with one another. The regions of the fibre web underneaththe compacting plate are held by the compacting plate on the drum. Atthe same time, only small regions of the fibre web between the trailingedge of the compacting plate and the row of water jets are subject tothe negative pressure. This too reduces the undesirable longitudinalstripes.

In a preferred embodiment, the spacing of the forward edge to the waterjet can be reduced to 0.1 mm, so that partial hydroentanglement is verypurposely carried out without stretching the fibre web in the regionbefore the rows of water jets.

A further improvement can be obtained by constructing the trailing edgeof the compacting plate to slide over the fibre web. By this means,orientation of the fibres on the surface of the fibre web is obtained,as a result of which increased longitudinal strength is achieved, butwithout any reduction in transverse strength.

Alternatively, the trailing edge of the compacting plate can beconstructed to roll over the fibre web. By that means, a linear pressureis exerted on the fibre web, with the impact on the MD/CD ratio being assmall as is possible.

An economical embodiment can be achieved by means of a compacting plateof metal, plastics or a composite material. It is then advantageous ifthe materials have a certain resilience or spring action and bendreadily. As a result, a run-in or compacting region is produced in whichthe fibres are compressed.

Advantageously, the compacting plate has a thickness of from 0.1 to 3mm, preferably of from 0.15 to 0.5 mm. Thin plates provide the necessaryresilience on bending. Especially in the case of thin spring steel orresilient materials the compacting plates can adapt to irregularities inthe material. Especially in the case of thin compacting plates, thespring action is sufficient so that the force on the fibre web islimited and does not tear off the fibre web.

In order to reduce friction and, as a result, to limit the influence onthe MD/CD ratio, the compacting plate can be provided with teflon or anano-coating.

By providing the trailing edge of the compacting plate with a wavy shapeor toothed arrangement, the fibre web can be better held on the drumwhen the drum is subject to a high degree of suction. Especially in thecase of thin plates, the wavy shape results in greater stability,because the trailing edge does not become partially bent or deformed asa result of the suction.

Alternatively, the trailing edge of the compacting plate can haveapertures or a perforated arrangement through which air can flow so thatthe compacting plate does not deform in the case of suction drainage byway of the suction slits of the drum or endless belt.

Irrespective of whether the compacting plate is fixed to a separatecarrier or to the water bar, it is advantageous that the spacing of thecompacting plate to the drum or endless belt is adjustable. As a result,on the one hand, the spacing from the water jet can be adjusted; on theother hand, the biasing of the resilient plate can also be defined.

The method according to the invention for hydrodynamic entanglement ofnon-wovens, wovens and knits, wherein a fibre web is transported betweena water bar and a drum or endless belt and entangled is characterised inthat the fibre web is, before the water bar, compressed on the drum orendless belt by means of a compacting device. As a result, a system isprovided which is shorter in overall length, which at the same time hassignificant advantages for the fibre web because compaction shortlybefore hydroentanglement prevents the fibres from floating.

Compressing the fibre web can alternatively be brought about by means ofa sliding or rolling compacting device, depending on whether amodification of the MD/CD ratio is desired. The trailing edge of thecompacting plate is then constructed accordingly.

In the case of a sliding compacting device, the strength of the fibreweb in the longitudinal direction can be increased. Direct entanglementby the water bar immediately after the compacting plate is moreeffective and therefore more efficient than entanglement with priormoistening in a compacting unit located upstream.

In accordance with the invention, a compacting device is integrated intoan entanglement system using the smallest space, with compacting takingplace just before entanglement. As a result, floating of the fibres isavoided, as a result of which the quality of the nonwoven increases andthe undesirable longitudinal stripes are avoided. In addition, as aresult of sliding compaction, the longitudinal strength can be increasedwithout this having an impact on the transverse strength.

The invention is explained in greater detail hereinbelow with referenceto a possible example of an embodiment shown in diagrammatic form,wherein:

FIG. 1: is a side view, in diagrammatic form, of an entanglement system;

FIG. 1 a: shows, to an enlarged scale, the entanglement region togetherwith a drum having suction drainage;

FIGS. 2 a-2 h: show various embodiments of the compacting plate;

FIG. 3: shows a further embodiment of an entanglement system;

FIG. 4: shows a further embodiment of an entanglement system.

FIG. 1 shows an entanglement system 1 which substantially comprises adrum 3 or, alternatively, an endless belt, having at least one water bar4. The drum 3 can be constructed in the form of a so-called screen drum,comprising a perforated plate drum, which is covered with a supportfabric and a fine screen or, alternatively, with a microporous shell.Alternatively, the drum can be in the form of a structured drum, thesurface of which is perforated in order to provide the fibre web 2 witha structure or pattern.

The drum 3 has a multiplicity of apertures 3 a, by way of which thewater from the water bar 4 is drained off. Within the drum 3 there isarranged a suction tube 3 c having a multiplicity of suction drainageslits 3 d, by way of which the water is drained off under negativepressure. Above the drum 3 there is arranged the water bar 4, whichsprays a series of water jets 6 under high pressure onto the fibre web 2by means of a multiplicity of nozzles 5. In accordance with theinvention, the water bar 4 is operated using a pressure of from 10 to100 bar, preferably using a pressure of from 20 to 40 bar. The nozzlebar 4 can be operated using one or more rows of water jets 6. Thenozzles 5 are arranged along the longitudinal axis of the water bar 4.For reasons of clarity, only one row of water jets 6 is shown. In thisexample of an embodiment, the fibre web 2 runs over the drum 3 in thedirection of the arrow from left to right and is struck continuously bythe water jets 6. The water bar 4 therein is arranged so as to beadjustable in its spacing from the drum 3 or endless web.

In the case of a structured drum, individual fibres extend into theapertures 3 a and intertwine with one another until they are pulled outfrom the aperture 3 a. When the drum 3 is provided with a suction tube,the fibre web 2 is at least partially sucked into the suction drainageslit 3 d, which can result in undesirable stripes on the entanglednon-woven.

In accordance with the invention, a compacting device 10 is arrangedbefore the water bar 4, seen in the running direction of the fibre web2, which compacting device 10 applies a pressure to the fibre web 2along the longitudinal axis of the drum 3. In this example of anembodiment, the compacting device 10 includes a suspension arrangement13 having an articulation 12 to which a carrier 11 is rotatably fixed.The suspension arrangement 13 is fixed to a machine frame (not shown) orstand. Beneath the carrier 11 there is arranged a compacting plate 14,which can be seen in side view. In its longitudinal extension, which isto say over the working width, the compacting plate 13 extends oversubstantially the entire length of the drum 3. In the region of a rearedge or run-in edge 14 b, the compacting plate 14 is fixed to thecarrier 11, whereas the forward or trailing edge 14 a presses the fibreweb 2 onto the drum 3 with biasing.

The compacting device 10 can be pivoted by means of the articulation 12,as a result of which the position of the contact-making surface orcontact-making line of the compacting plate 14 on the fibre web 2 isadjustable. At the same time, as a result of rotation of the compactingdevice 10 about the articulation 12, the pressure of the compactingplate 14 on the fibre web 2 can be modified. For that purpose it isadvantageous if, in addition to the articulated arrangement of thecompacting device 10, the latter is constructed so that its height isadjustable. For that purpose, the suspension arrangement 13 can be ofadjustable construction. As a result the pressure or force applied tothe fibre web 2 can be adjusted in dependence on the fibres beingprocessed. The compacting plate 14 can be made, for example, from astrip of metal or plastics which can be readily bent by the pressure ofthe compacting device 10 and so press resiliently on the fibre web 2.The free end or trailing edge 14 a of the compacting plate 14 hereinpoints in the running direction of the fibre web 2.

The technical effect of the compacting device 10 lies in the fibre web 2being compressed within a very small space before entanglement by thewater bar 4 occurs. The system can be of substantially shorterconstruction than a compacting device having rolls or belts according tothe prior art. A further advantage lies in the fact that the compactingproduces compression of the fibres shortly before entanglement by thewater jets, as a result of which floating of the individual fibres isprevented, which ultimately results in a better non-woven product.

Compacting just before the water jet 6 is essential to the invention, asa result of which the fibre web 2 is prevented, in relatively largeregions before the row of water jets 6 and/or as a result of thenegative pressure in the suction tube 3 c, from being sucked into thedrum 3 in the direction of production, with the non-woven undergoingdeformation. If the suction is uneven, transverse corrugations can beproduced in the non-woven, and also longitudinal stripes. At the sametime, the strength of the fibre web 2 in the longitudinal direction canincrease whereas the strength of the fibre web 2 in the transversedirection remains the same. Conventionally, when fibre webs stretch,there is a change in the MD/CD ratio in both directions, that is to say,for example, the strength increases in the longitudinal direction butdecreases in the transverse direction or vice-versa. The compactingplate 14 on the other hand can, as a result of the compacting actionshortly before entanglement by the water jets, increase the strength inthe longitudinal direction of the fibre web 2, because the trailing edge14 a only slides over the surface of the fibre web 2. In contrast, overthe cross-section of the fibre web 2 as a whole, no change in theorientation of the fibres takes place. A further advantage arises out ofthe fact that the disadvantageous longitudinal stripes or longitudinalstructures are prevented by means of the compacting plate, because thefibre web 2 is pressed onto the drum 3 in the longitudinal direction ofthe drum 3 and only the partial region or strip between the compactingplate 14 and the water jets is stretched and the fibres intertwined withone another.

FIG. 1 a shows, to an enlarged scale, a view of the entanglement regionwithout the suction tube 3 c arranged within the drum. In contrast tothe embodiment according to FIG. 1, the aperture 3 a has a run-in region3 b arranged before the water jet 6, seen in the running direction ofthe fibre web 2. The aperture 3 b of the suction drainage slit 3 a is ofwedge-shaped construction so that the suction force caused by thenegative pressure in the suction slit increases only slowly and thenon-entangled non-woven is compressed slowly without displacement of thefibres due to suction air.

In this example of an embodiment, the trailing edge 14 a of thecompacting plate 14 is arranged close up to the water jet 6 and, in sodoing, covers over the run-in region 3 b at least in part. As a result,the fibre web 2 is pushed onto the drum 3 along the longitudinal axis ofthe drum 3 by the compacting plate 14. Only the fibres which arearranged in the region of the aperture 3 a and the run-in region 3 b areintertwined with one another.

Only small regions of the fibre web 2 which are located in the region ofthe run-in region 3 b are pulled into the aperture 3 a by the negativepressure of the suction drainage.

The spacing of the trailing edge 14 a of the compacting plate 14 fromthe water jet 6 can be reduced to 0.1 mm so that partialhydroentanglement can be very purposely achieved without stretching thefibre web 2 in the region of the suction drainage slit 3 a. The trailingedge 14 a of the compacting plate 14 can, however, also be arranged onthe drum 3 or belt with a larger spacing from the water jet 6. Theadvantage then lies in the space-saving arrangement of the compactingdevice according to the invention, with its being possible for thestrength of the web to become greater as a result of the constructionwith the compacting plate.

FIGS. 2 a to 2 f show various arrangements of a compacting plate 14,wherein in the simplest embodiment according to FIG. 2 f the compactingplate 14 has a straight trailing edge 14 a.

In FIG. 2 a, the trailing edge 14 a of the compacting plate 14 isprovided with a rotatable roller 20, which although applying a linearpressure to the fibre web rolls on the surface of the fibre web so thatthe impact on the MD/CD ratio is as small as possible.

In the subsequent FIGS. 2 b to 2 e, the compacting plate 14 with itstrailing edge 14 a is so constructed that it slides over the fibre weband, in so doing, orientates the fibres on the surface as desired—independence on the pressure—in the longitudinal direction or, that is,the running direction.

The compacting plate 14 according to FIG. 2 b has on its trailing edge14 a a beading 14 c, in which a sliding element 21 can be accommodatedand/or fixed. The sliding element 21 can be in the form of a round baror strip and be made of, for example, teflon or some other verylow-friction plastic. The sliding element 21 can extend preferably overthe entire length of the compacting plate 14 but of course also only insections.

According to FIG. 2 c, the compacting plate 14 has a large radius at theround trailing edge 14 a, which acts as a rounded contact-making memberand which slides especially gently over the fibre web 2. As a result,orientation of the fibres on the surface of the fibre web 2 is reduced.

The opposite is achieved using the arrangement of a compacting plate 14according to FIG. 2 d. The trailing edge 14 a acting on the fibre webhas been given a very sharp edge so that orientation of the fibres onthe surface of the fibre web 2 is maximised.

In the arrangement according to 2 e, a compacting plate 14 having arectangular cross-section at the trailing edge 14 a is shown, whereinthe edges are only slightly rounded. In this embodiment, the compactingplate is of very thin construction and is straight in the unloadedstate, as in FIG. 2 f, so that it bends in the region of thecontact-making surface. As a result, owing to the curve in the plate, anarea, and not a line, is applied to the fibre web 2. Alternatively, thecompacting plate 14 can also be pre-bent so that with less pressure alarger area can however be worked.

The compacting plate can be made in a thickness of from 0.1 to 3 mm,preferably in a thickness of from 0.15 to 0.5 mm, it being possible forthe pressure to be adjusted in dependence on the spring action. Normalsheet metals, stainless steel sheets, spring steel sheets, flexible orrigid plastics strips can be used as materials. In order to reducefriction with the fibre web and have minimum impact on the MC/CD ratio,the compacting plates 14 can be provided, for example, with teflon or anano-coating.

In contrast, should it be desired to influence the MD/CD ratiopurposely, there is of course also the possibility of structuring and/orroughening the surface of the compacting plates.

FIG. 2 g shows a top view onto a compacting plate 14, in which thetrailing edge 14 a extends, not in a straight line as in FIGS. 2 a to 2e, but rather in a wavy shape. The advantage lies in the fact that thetrailing edge 14 a attains greater stability because the trailing edge14 a does not undergo partial bending and/or deformation in the regionof the aperture 3 a and/or run-in region 3 b, especially in the case ofthin plates. A like effect is achieved by a compacting plate having aroughly toothed arrangement.

Also to be seen in this context is the embodiment according to FIG. 2 h,wherein at least the trailing edge 14 a of the compacting plate 14 hasapertures 14 d or a perforated arrangement through which air can flow.This compacting plate too will not undergo substantial deformation inthe region of the aperture 3 a in the case of strong suction drainage.The apertures 14 d can have a diameter in the millimetre range, forexample from 0.5 to 3 mm, but they can also be of much finerconstruction, in which case they are then referred to asmicro-perforation. In dependence on the fibre mixture to be processed,it is possible to influence the fibre quality and surface by means ofthe arrangement and size of the apertures 14 d.

In the example of an embodiment according to FIG. 3, the compactingdevice 10 is provided with a contact pressure application apparatus 16,which presses the carrier 11 with the compacting plate 14 onto the fibreweb 2. In this Figure, the contact pressure application apparatus 16 isshown symbolically as a spring. It can consist of a hydraulic orpneumatic cylinder or be of spring-loaded construction. In this exampleof an embodiment, the rear edge 14 b of the compacting plate 14 isarranged underneath the carrier 11 by means of a fixing 15. As in theexample of an embodiment according to FIG. 1, it is possible, by meansof the articulation 12, for the position of the contact-making surfaceor contact-making edge of the trailing edge 14 a to be adjusted, andalso, in addition, the force which is applied to the fibre web 2, byslightly bending the compacting plate 14.

In FIG. 4, in contrast to FIG. 1, an endless belt 7 rather than the drumis arranged in the entanglement system 1, on which endless belt 7 thefibre web 2 is entangled by means of water jets 6. The endless belt 7can be in the form of a screen belt in order to drain off the waterrapidly. Underneath the endless belt 7, in the region of the nozzle,there is shown a suction tube 3 c in the form of a rectangular box,which likewise has at least one suction drainage slit 3 d. In contrastto the previous embodiments, the compacting plate 14 is arranged on andfixed to the water bar 4 directly. The fixing 15 in the region of therear edge 14 b can be made on a side wall of the water bar 4 or also, ofcourse, on the bottom surface in the region of the nozzles 6. This hasthe advantage that the trailing edge 14 a can be oriented very wellrelative to the water jet 6. It is self-evident that the lateral fixing15 on the water bar 4 can also have, inter alia, a height adjustmentfacility so that the pressure on the fibre web 2 is adjustable by meansof the spring action of the bent compacting plate. The arrangementdirectly on the water bar is a space-saving solution, in which allpreviously mentioned adjustment capabilities, in terms of spacing orheight or angle, can likewise be implemented.

REFERENCE NUMERALS

-   1 entanglement system-   2 fibre web-   3 drum-   3 a aperture-   3 b run-in region-   3 c suction tube-   3 d suction drainage slit-   4 water bar-   5 nozzle-   6 water jet-   7 endless belt-   10 compacting device-   11 carrier-   12 articulation-   13 suspension arrangement-   14 compacting plate-   14 a trailing edge-   14 b lead-in edge-   14 c beading-   14 d aperture-   15 fixing-   16 contact pressure application apparatus-   20 rotatable roller-   21 sliding element

1. Apparatus for hydrodynamic entanglement of non-wovens, wovens andknits, comprising an entanglement system having at least one water barand a drum or endless belt, between which a fibre web is transported andentangled, characterised in that before the water bar, seen in therunning direction of the fibre web, there is arranged a compactingdevice, which is integrated on or into the entanglement system and whichcompresses the fibre web on the drum or endless belt, the compactingdevice having at least one compacting plate, which presses the fibre webonto the drum endless belt.
 2. (canceled)
 3. Apparatus according toclaim 1, characterised in that the compacting plate is arranged to befixed to the water bar.
 4. Apparatus according to claim 1, characterisedin that the compacting plate is arranged to be fixed to a carrier. 5.Apparatus according to claim 3, characterised in that the carrier isarranged to be pivotable.
 6. Apparatus according to claim 1,characterised in that the compacting plate compresses the fibre web withbiasing.
 7. Apparatus according to claim 6, characterised in that thebiasing is produced by means of the resilience of the compacting plateand/or by a contact pressure application apparatus.
 8. Apparatusaccording to claim 1, characterised in that a forward edge or trailingedge of the compacting plate is positioned directly at the water jet. 9.Apparatus according to claim 8, characterised in that the trailing edgeof the compacting plate covers over at least part of the suction regionsof an aperture and/or run-in regions arranged in the drum.
 10. Apparatusaccording to claim 8, characterised in that the spacing of the trailingedge to the water jet is arranged to be reduced to 0.1 mm.
 11. Apparatusaccording to claim 1, characterised in that the trailing edge of thecompacting plate is constructed to slide over the fibre web. 12.Apparatus according to claim 1, characterised in that the trailing edgeof the compacting plate is constructed to roll over the fibre web. 13.Apparatus according to claim 1, characterised in that the compactingplate is made of metal, plastics or a composite material.
 14. Apparatusaccording to claim 1, characterised in that the compacting plate has athickness of from 0.1 to 3 mm, preferably of from 0.15 to 0.5 mm. 15.Apparatus according to claim 1, characterised in that the compactingplate is provided with teflon or a nano-coating.
 16. Apparatus accordingto claim 1, characterised in that the trailing edge of the compactingplate has a wavy shape or toothed arrangement.
 17. Apparatus accordingto claim 1, characterised in that the trailing edge of the compactingplate has apertures or a perforated arrangement.
 18. Apparatus accordingto claim 1, characterised in that the spacing of the compacting plate tothe drum or endless belt is adjustable.
 19. Apparatus according to claim1, characterised in that the pressure of the water bar is between 10 and100 bar, preferably between 20 and 40 bar.
 20. Method for hydrodynamicentanglement of non-wovens, wovens and knits, wherein a fibre web istransported between a water bar and a drum or endless belt andentangled, characterised in that the fibre web is, directly before thewater bar, compressed on the drum or endless belt by means of acompacting device so that floating of the fibres is prevented. 21.Method according to claim 20, characterised in that compressing isbrought about by a compacting device sliding or rolling on the fibre web22. Method according to claim 20, characterised in that, as a result ofthe compaction, the strength of the fibre web in the longitudinaldirection is arranged to be increased